Implementation of Targeted Axillary Node Assessment Following Neoadjuvant Therapy for Node-positive Breast Cancer Patients Improves Axillary Disease Detection

Abstract

Background: Assessing the targeted node, a biopsy-proven metastatic node marked with a metallic clip before neoadjuvant chemotherapy along with sentinel node dissection improves the evaluation of pathological response in the axillary nodal basin after systemic treatment as compared to sentinel node dissection with dual tracer alone. Objectives: The objective was to investigate the rate of the clipped node being a sentinel node and the sensitivity of targeted node dissection in detecting residual disease. Methods: A prospective study of biopsy-confirmed breast axillary nodal metastases with a metallic clip placed before initiating systemic therapy. After the therapy, the clip node was identified by ultrasound-guided needle localization and sentinel node biopsy by the dual tracer. At least 3 or more nodes were sent for biopsy. Nodal metastasis was confirmed by frozen section biopsy and complete axillary dissection was done even if micro-metastatic disease was detected. Results: Of 120 patients enrolled in the study, 60(50%) patients had residual axillary nodal disease after neoadjuvant chemotherapy. Among 60 patients with positive residual disease clip node was positive for metastasis in all node-positive patients 60 (100%).  Among these 60 patients with residual disease in 42 (70%) cases clipped nodes and sentinel nodes were alike/same, whereas the remaining 18 (30%) patients with residual disease clipped nodes were not sentinel nodes. In the 10/18 case, the sentinel node was also positive on biopsy or complete axillary clearance but in 8/18(13%) nodes that were clipped but not sentinel nodes clip node was only positive node, but the sentinel node was negative on frozen well as on complete axillary clearance. This emphasizes the importance of clipped node removal/assessment after neoadjuvant surgery without which we can miss about 13% of positive axillary disease. Conclusion: Marking nodes (metallic clip) with biopsy-confirmed metastatic disease allows for selective removal and improves pathologic evaluation for the residual nodal disease after chemotherapy.